Expandable reel mandrel



TMarch 3, 1959 P. e. FORET ETAL EXPANDABLE REEL MANDREL 2 Sheets-Sheet 1 Filed Feb. 4, 1957 [FIG.

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March3, 1959 P. e. FORET ETAL EXPANDABLEZ REEL. MANDREL 2 Sheets-Sheet 2 INVENTORS. PIERRE e. FORET and BY ROBERT syms Filed Feb. 4, 1957 -ATTORNEY.

N moyethe reel therefrom.

EXPANDABLE MANDREL Pierre G. Foret, Framingham, and Robert E. Wilkins, Wollaston, Mass, assignors, by mesne assignments, to Minneapolis-Honeywell Regulator Company, a corporation of Delaware Application February 4, 1957, Serial No. 638,159

' 4 Claims. c1. 192 -76) started'and stopped in motion without any slippage ofthe reel upon the mandrel. 7

. -A known form of reel mounting. mandrel comprises a pair 'of cylindrical clutch elements mounted about a drivingxaxis'of a mandrel where the clutch elements are adapted to' be expanded into engagement with the inner surface of a reel which is to be carried thereby- The mounting of a'heavy red on a rotatable mandrel creates numerous problems particularly where the reel must be repeatedlystarted and stopped. In apparatus of the circumferential'brake type heretofore available, the reel has -been:subject to slippage upon the mandrel causing re- -sultant'gwear of .the' mandrel clutchingsurfaces and thereby considerably :reducing the useful life of the mandrel and-atthe sametime increasing the maintenance problems-:with :res'pect thereto. If the slippage and wear associatedwith the mandrel go undetected, the operational hazards .withrespect to operating personnel and associated equipment may also be considerable. The provi- .sion of a' greater. clutching action on the mandrel by itself creates another problem that is inconsistent with the need for the reel tobe readily removable'from the mandrel with a;minimum of elfort on the part ofthe using personneL.

. Itis accordinglyia more specific object of the present invention to provide a new and improved rotatable 'mandrelj-whichjis adapted to carry a reel where the mandrel is to be started and stopped repeatedly with means for .insuringa firm locking'relationship between the reel and the mandrel-in combination withv means. for. readily acti- .yating the clutching surfaces of the mandrel and releas- United States Patent invention;

2,875,874 Patented Mar. 3, 1 959 ice . 2 actuated by a minimum of efiort on the part of an operator.

This new and novel linkage is arranged with respect to the mandrel so that the linkage may be moved in such a way that it does not interfere with an-operator placing a reel on the mandrel or removing a reel therefrom.

A further requirement of some forms of apparatus of the present type is that a positive mechanical lock be provided for the reel in addition to the normal clutching actionapplied thereto by the reel mandrel. This has been accomplished in the present invention by means of extending the link which drives the clutch actuating toggle so that the link may project into the rim of the associated reel and thereby positively lock the reel in position while the toggle is holding the clutch members of the mandrel inthe active clutching position.

It is then a still further object of the invention to provide a new and improved reel mandrel in accordance with the. foregoing objects wherein a ,clutch actuating toggle drive link is extended so that it may be used to positively engage a reel mounted on the mandrel.

The foregoing objects and features of novelty which I characterize the invention as well as other objects of the invention are pointed out with particularity in the claims annexed to and forming a part of the specification. .For a. better understanding of the invention, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive Figure 2 shows a sectional side view of the reel mandrel of the present invention;

Figure 3 shows a top plan view of the reel mandrel shown in Figure 2;

i Figure 4' is a diagrammatic showing. of the clutch ingthe clutching. surfaces to permit an operator'to firmly lock theassociated reel on the mandrel and-readily re- -.-.The- ;foregoing object .ofthe present invention is achieved by a" new and novel combination of linkage means and levers soarranged that a simple mechanical IllQIlOIlT OH-lhC partof an operator will be effective to move .a'pair-of clutching-braking surfaces'carried by'the mandrel into alocking position where thelin'ks associated with the-clutch are toggled to-thereby lock the brake shoes on t he, mandrel. In addition, a driving linkfor the toggle isprovided whereby the toggle may be moVedinto and out of the locking position'with a minimum of effort; on the part of an operator.

It is therefore a still furthermore specific object of the-.present invention -to provide a new and improved mandrel which is .arrangedto detachably support a reel to be rotated where the mandrel has a very high gripping action-.on the inner surface of the reel with this gripping shoes and the toggle actuating means for the clutchesin combination with the toggle drive link;

.Figure 5 shows a perspective view of the toggle linkage forthe clutch assembly of Figure 4 with a portion of vthedriving lever for the toggle drive link also shown;

Figure 6 is a diagrammatic showing of how the principles of the present invention may be extended to a double toggle clutch actuating mechanism; and Figure 7- shows a side view of the actuating levers and the toggle drive linkages for apparatus of the type shown -inFigure 6. I

:Referring first to Figure 1, the numeral 10 represents a panel or support upon which are mounted elements associated with a record tape transport mechanism-useful, for example, inthe storing of information on the tape 'utilized therein: Carried by the support 10 are a pair of tape supply reels 11 and-12 which are adapted to be reversibly driven by support mandrels 13 and 14, respectively, by-motor means, not shown, but supported on the 0 reverse sideof the panel 10. The reels l1 and 12 are adapted to carry a tape 15 which may take the form of a magnetic, tape upon which information may be stored by electrical impulses The tape 15 is arranged to pass through a pair ofloop chambers 16 and 17, said loop chambers being arranged to maintain the tape 15 under tension due to the action of the atmospheric pressure exerted on the top of the tape and the reduced pressure created under the tape in the loop chamber by a suitable suction means connected to the outlet conduits 18.

' The-tape 15 is guided into the loop chambers 16 and 17, by suitableguide and tensioning pins 19 and 20 as well as by the guide pins 21 and 22. The guide pins 19 and 20, together with the force on the tape due to the pressure in the loop chamber, function to maintain the tape 15 under tension as it is fed onto the respective reels 11 and 12. This prevents the tape from forming pockets and bulging as it is wound on the reel 11 or 12.

A suitable informational transfer head 25 is positioned to engage the tape 15, the latter of which is moved past the transfer head by a pair of contra-rotating capstans 26 and 27 which are of the pneumatic type. Positioned between the capstans 26 and 27 is a pneumatic brake 28. The sudden application of a reduced pressure to either of the capstans 26 or 27 or the brake 28 is used to selectively. control the movement or stopping of the tape 15 withrespect to the transfer head 25.. The controlling of the pressure supplied to the capstans and the brake is by way of a suitable pneumatic switching means 29.

In considering the operation of the apparatus shown in Figure 1, it should first be noted that, whether for tape recording or reading purposes, it is desired to move the tape 15 past the information transfer head 25. The movement of the tape must be at some predetermined speed which is suitable for producing a transfer of information between the head and the tape. Such a speed may be, for example, one hundred inches per second and the capstan diameter and rotational speed are so selected as to produce this linear surface speed. The driving of the tape 15 past the head is accomplished by either one or the other of the driving capstans 26 and 27. If it is desired to drive the tape from left to right past the reading head 25, the capstan 27 is actuated by the pneumatic switch 29 so that a subatmospheric pressure is applied to the capstan 27 to result in the tape being drawn into engagement with the capstan so that the rotation is transferred to the tape when it is moved in the desired direction. Should it be desired to move the tape in the opposite direction, the capstan 26 will be actuated by the application of a subatmospheric pressure thereto by the switch 29 and this will cause the tape to be drawn against the capstan 26 so that the tape will be moved in the desired direction.

When it is desired to stop the tape, the pneumatic switch 29 is effective to disconnect the subatmospheric pressure from the capstan previously driven and apply the pressure to the brake 28. The brake member will in turn draw the tape against the face of the brake and cause the tape to stop.

For a more detailed consideration of the capstan and brake assembly illustrated in Figure 1, reference should be had to the co-pending application of Robert A. Pendleton entitled Control Apparatus bearing Serial Number 586,209, filed May 21, 1956.

The tape reels 11 and 12 are arranged to be driven by motor means, not shown, to maintain the desired amount of tape within the loop chambers 16 and 17. The depth of the tape in the respective loop chamber may be detected by suitable photoelectric means, or pressure sensing means. When the tape is being driven from left to right, the tape 15 will tend to fill up the chamber 17. As the tape extends further into the chamber 17, the reel 11 must be operated to pull a suitable length of tape out of the chamber onto the reel. Inasmuch as the effective diameter of the reel will vary with the amount of tape thereon, it will be apparent that the reel 11 can not be driven at a uniform speed in order to remove the tape 15 from the chamber 17. Consequently, the reel 11 must be repeatedly stopped and started in order to take up the tape from the loop chamben It will be apparent that with respect to the chamber 16 when the tape is being driven by the, capstan 26, the reel 12 must be used to take up the excess tape from the chamber. For the reasons set forth with respect to the reel 11, the reel 12 must also be driven at periodic intervals as it is not practical to maintain a varying speed on the tape reel in order to compensate for variations in the effective diameter of the reel due to the amount of tape thereon. It will be apparent that the reels 11 and 12 must also,be driven to supply tape to the loop chambers 16 and 17 to maintain a desired 4 amount of slack tape on either side of the driving capstans. This too necessitates repeated starting and stop ping of the active feed reel.

From the foregoing discussion of Figure 1, it will be apparent that the reels 11 and 12 are periodically stopped and started and also driven in a forward or reverse direction. In one particular embodiment of the present invention, the reels 11 and 12 utilized an inner hub which was ten inches in diameter and the rell itself, when fully loaded with magnetic tape weighed approximately twenttwo pounds. It will thus be appreciated that the torque exerted on the reel by the drive mandrels associated therewith during this repeated starting and stopping is extremely high. The resultant high accelerations and decelerations require a very effective mandrel which will grip the reel to prevent any slippage of the reel on the mandrel. Further, the reels of the apparatus must be adapted for ready removal to permit an operator to change reels without undue elfort or delay.

Considering now the reel mandrel more specifically. and noting particularly Figures 2 through 5, it will be seen that the mandrel comprises a basic drive hub for the mandrel 14, as shown in Figure 2, which comprises a cast member 35 suitably drilled and threaded so that it may be readily attached and locked to a drive shaft, not shown. The hub 35 has a cylindrical portion 36 upon which is supported a cylindrical member 37, the latter of which is adapted for axial displacement by means of a handle 38. The cylindrical member 37 carries a member 39, which is slotted at 40, and a protective cover plate 41.

A reel guide and support plate 42 is mounted on the hub 35 and this support plate is arranged to carry the clutch members 43 and 44, as shown best in Figure 4. The clutch members 43 and 44 are pivotly supported by a pair of eccentric pivot members 45 and 46, the latter permitting the outward expansion of the clutch shoes or members 43 and 44 and in addition providing a means for aligning the shoes by the eccentric adjustment of the pivots. The clutch shoes have a T shaped cross section with the upright of the T section being sufliciently small enough to permit the shoes to be flexible to engage the associated reel over. a wide surface.

Carried in the support member 42 on the side opposite the pivoting members 45 and 46 is a toggle drive link 47, the latter of which is journaled in suitable bearing surfaces 48 and 49 for radial movement with respect to the drive axis of the mandrel. Carried by the toggle drive link 47 is a ball joint 50 having a pin 51 extending therethrough,

the latter being an extension of a lever 52. The lever 52 is pivoted at 53 and the opposite end is positioned in the slot 40 of the member 39. It will be noted from the view .in Figure 3 that the lever 52 is actually comprised of separate members which are split so as to pass around I the hub 35 and then come back together again to a com- 55 in the member '39.

mon pin 55, the latter of which projects through the slot Carried by the toggle drive link 47 is a block 56, the

' latter having a pair of pins 57 and 58 extending therefrom. The block 56 is threadedly mounted on the drive link 47 to provide an adjustment of the throw of the link 47 when the pin 51 extends through the drive link 47, the

. relationship of the block 56 on the link 47 is locked. The

pins 57 and 58 on block 56 are in turn used to act as pivots for the clutch toggle which comprises a pair of links 59 for clutch shoe 43 and a pair of links 60 for the clutch shoe 44. The links 59 co-operate with a pivot pin 1 63 on clutch shoe 43 and the links 60 co-operate with a "tions, the operator handle 38 may be moved to .the left to the dotted line position shown in Figure 2. This will cause the lever 52 to be moved in a clockwise direction about the pivot 53 to'thereby cause the pin 51 extending from the lever 52 to move the toggle drive-link 47 in an inward direction. This will cause the toggle links 59 and 60 to be moved in a downward direction and thereby move the clutch shoes 53 and 54 inwardly to an inactive position. The toggle drive link 47 will be withdrawn within the surface of the support 42. The mandrel is now ready to receivea reel such as a reel of tapeshown at 12. in Figure 1 as well as in partial section in Figure 2. i

The operator will place the reel upon the mandrel so that the reel surface 12A comes into engagement with the extension of the support member 42. It will be noted that the extension of the supporting member 42 has a slight taper to permit the ready placement of the reel on. the mandrel. When the reel is in place, the operator merely depresses the handle 38 to the solid line position shown in Figure 2. This motion is effective to drive the lever 52 in a counter clockwise direction. This will in turn drive the toggle drive link 47 outward so that the toggle links 59 and 60 will force the clutching shoes 43 and 44 outward to engage the inner surface of the reel 12. This will lock the reel 12 on the mandrel. In addition, the outward extension of the drive link 47 may be arranged to extend into the aperture 61 in the reel 12 to provide a positive mechanical lock in addition to the clutching lock from the clutching shoes 43 and 44.

It will be apparent from the foregoing description that the present apparatus is capable of providing an extremely large clutching force upon the inner surface of the tape reel 12 due to the novel linkage arrangement which produces a very high mechanical advantage. The high mechanical advantage is achieved by the linkage which is arranged to in no way interfere with the operator placing a reel on the mandrel. This is due to the fact that the only mechanical movement is an axial movement of the handle 38 with respect to the drive hub 35, said movement not extending the linkage into the path of the reel as placed or removed from the mandrel. In one embodiment of the invention, a force of 3.5 pounds on the handle 38 was effective to produce a force of 182 pounds at the clutching surface. This force at the clutching surface permitted a torque of 32 foot pounds to be applied to the reel carried by the mandrel without any perceptible slippage of the reel on the mandrel as the reel was periodically stopped and started.

When the clutch toggle links 59 and 60 are moved to the active position as shown in Figure 4, the toggle links 59 and 60 will be slightly past center. Since they are slightly past center, they tend to exert an outward force on the drive link 47 and a force on the lever 52 which is in a counter clockwise direction. However, due to the fact that the cylindrical member 37 which carries the handle 38, is down against the inner portion of the hub 35, there is an effective lock on the clutch shoes with the lock being retained until the handle 38 is used to move the toggle back from its overcenter or locked position.

It will be readily apparent that the principles of the present invention may be expanded to include other types of mandrels. For example, the mandrel shown in Figure 6 in partial detail is an extension of the type of mechanism ages67 and 69 simultaneously. Further, this mechanism will provide a larger mechanical advantage to drive the clutching surfaces 65 and 66 from the inactive to the, active position.

One embodiment of this modified versionv of the present invention achieved a mechanical advantage such that a force of 3.5 pounds on the handle produced a force of 300 pounds on the clutch members.

7 It will :be apparent from the foregoing description that there has been provided a new and improved mandrel which is adapted to exert a high clutching and locking force upon the reel to be carried thereby and this clutching force may be achieved by a minimum effort on the part of the operator who places the reel upon the mandrel. It will further be apparent that the material selected for the clutch-shoes and for the other materials must be selected to withstand the forces and pressures inherent in the particular application of the mandrel, and that various combinations of materials will be acceptable.

While, in accordance with the provisions of the statutes, there has been illustrated and described the best forms of the invention known, it will be apparent to those skilled in the art that changes may be made in the apparatus described without departing from the spirit of the invention defined by the claims and that in some cases, certain features of the invention may be used to advantage without a corresponding use of other features.

Having now described the invention, what is claimed as new and novel and for which it is desired to secure by Letters Patent is:

l. A reel mandrel comprising a pair of arcuate clutch members adapted to be radially expanded, a pair of links pivotally connected together by a first pivot at one end and each having the other end pivotally connected to the ends of said clutch members and arranged so that movement of said first pivot in an outward radial direction moves said clutch members apart, a second pivot mounted on said mandrel between said first pivot and a hub positioned at the central axis of said mandrel, a lever mounted on said second pivot, said lever extending on one side of said second pivot to engage said pair of links and extending on the other side of said second pivot to a point beyond said hub, a directly operable manual actuating handle adapted to be axially displaced along said hub, said handle having an outside peripheral dimension which is less than the peripheral dimensions of said clutch members, a slotted channel member carried by said handle, and means pivotally connecting the end of said other side of said lever to the slot in said channel member.

2. A reel mandrel comprising a pair of arcuate clutch members adapted to be radially expanded, a pair of links pivotally connected together by a first pivot means at one end and each having the other end pivotally connected to the ends of said clutch members and arranged illustrated in Figures 2 through 4. Here, a toggle linkage is provided at both adjacent ends of a pair of clutch shoes and 66. An upper toggle linkage 67 is arranged to be actuated by a lever 68 while a lower toggle linkage 69 is adapted to be activated by a lever 70. Levers 68 and 70 may well take the form of the lever 52 with one portion thereof extending around the central hub which carries the operating handle, such as the handle 38 shown in Figure 2. Each of the levers 68 and 70 may be arranged to engage a member carried by the handle which has been slotted as is the member 39 used to activate so that movement of said first pivot in an outward radial direction moves said clutch members apart, said first pivot means comprising an elongated member mounted on said mandrel along a radius thereof and positioned within a bearing means for longitudinal movement, said member having an opening therein adapted to receive one end of an actuating means, a second pivot mounted on said mandrel between said first pivot and a hub positioned at the central axis of said mandrel, a lever forming said actuating means mounted on said second pivot, said lever extending on one side of said second pivot to engage said first pivot means at the opening of said elongated member and extending on the other side of said second pivot to a point beyond said hub, a directly operable actuating handle adapted to be axially displaced along said hub, a slotted channel member carried by said the lever 52 in Figure 2. It will be apparent th t th handle, and means connecting said other side of said lever levers 68 and 70 will be used to activate the toggle linkto the slot in said channel member.

3. A reel mandrel as defined in claim 2 wherein said elongated member is adapted to extend beyond the periphery ofsaid clutch members and betweensaid clutch members when said lever has been moved to an actuated position wherein said clutch members are expanded.

4. A reel mandrel comprising a pair of arcuate clutch members adapted to be readilly expanded, a pair of links pivotally connected together by a first pivot means at one end and each having having the other end pivotally connected to the ends of said clutch members and arranged so that movement of said first pivot in an outward radial direction moves said clutch members apart, said first pivot means comprising an elongated member mounted on said mandrel along a radius thereof and positioned-within a bearing means for longitudinal movement, said member carrying a ball joint pivot with a cylindrical opening therein, a second pivot mounted on said mandrel between said first pivot and a hub positione'd at the central axis of said mandrel, a lever mounted on said second pivot, said lever extending on one side of said second pivot to project into said ball joint pivot and extending on the other side of said second pivot to a point beyond said hub, a directly operable actuating handle adapted to be axially displaced along said hub, a

slotted channel member carried by said handle, and

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